[PATCH v2 2/3] net/tcp: Separate tcp_md5sig_info allocation into tcp_md5sig_info_add()

Dmitry Safonov
2022-11-03T21:25:51Z

Add a helper to allocate tcp_md5sig_info, that will help later to
do/allocate things when info allocated, once per socket.

Signed-off-by: Dmitry Safonov <dima@arista.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
---
net/ipv4/tcp_ipv4.c | 30 +++++++++++++++++++++---------
1 file changed, 21 insertions(+), 9 deletions(-)

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 87d440f47a70..fae80b1a1796 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1172,6 +1172,24 @@ struct tcp_md5sig_key *tcp_v4_md5_lookup(const struct sock *sk,
}
EXPORT_SYMBOL(tcp_v4_md5_lookup);

+static int tcp_md5sig_info_add(struct sock *sk, gfp_t gfp)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ struct tcp_md5sig_info *md5sig;
+
+ if (rcu_dereference_protected(tp->md5sig_info, lockdep_sock_is_held(sk)))
+ return 0;
+
+ md5sig = kmalloc(sizeof(*md5sig), gfp);
+ if (!md5sig)
+ return -ENOMEM;
+
+ sk_gso_disable(sk);
+ INIT_HLIST_HEAD(&md5sig->head);
+ rcu_assign_pointer(tp->md5sig_info, md5sig);
+ return 0;
+}
+
/* This can be called on a newly created socket, from other files */
int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr,
int family, u8 prefixlen, int l3index, u8 flags,
@@ -1202,17 +1220,11 @@ int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr,
return 0;
}

+ if (tcp_md5sig_info_add(sk, gfp))
+ return -ENOMEM;
+
md5sig = rcu_dereference_protected(tp->md5sig_info,
lockdep_sock_is_held(sk));
- if (!md5sig) {
- md5sig = kmalloc(sizeof(*md5sig), gfp);
- if (!md5sig)
- return -ENOMEM;
-
- sk_gso_disable(sk);
- INIT_HLIST_HEAD(&md5sig->head);
- rcu_assign_pointer(tp->md5sig_info, md5sig);
- }

key = sock_kmalloc(sk, sizeof(*key), gfp | __GFP_ZERO);
if (!key)
--
2.38.1